| 摘要 |
A method of creating thermally stratified mixture for HCCI engines to prolong the combustion duration, thereby operate the engine with higher loads. An electrical heating coil of suitable rating with electrical insulation is embedded in the cylinder head. During the compression stroke the electricity is supplied to the coil and is cut off at a point near to TDC. The part of the mixture which comes into contact with the electrical coils gets heated. This creates thermal gradients within the mixture being compressed. The autoignition of the fuel will be initiated at the zones where the temperature is the highest, which is due to electrical heating and compression. As the rest of mixture is at relatively lower temperatures, there will be a finite delay for the remaining mixture to get ignited. By using this method, HCCI combustion of the mixture within the cylinder can be achieved at different regions at different timings which will lead to longer durations of overall combustion. The electrically heated coil serves two purposes in this method; one is to promote autoignition and the other is to create thermally stratified mixture in the cylinder. |
